ASA 128th Meeting - Austin, Texas - 1994 Nov 28 .. Dec 02

4pSP5. The articulatory kinematics of two levels of stress contrast.

K. Bretonnel Cohen

Mary E. Beckman

Linguist. Dept., Ohio State Univ., Columbus, OH 43210-1298

Jan Edwards

Marios Fourakis

Ohio State Univ.

Intonation pattern and syllable duration are thought to be the most
salient perceptual cues to phrase stress. However, intonation is an inherently
ambiguous cue, since not all English pitch accents involve higher pitch on the
accented syllable, and because there are stress contrasts at a lower level,
where stress cannot be equated with accentuation. Duration, too, is ambiguous,
since it can cue other prosodic contrasts, such as phrasal position. This study
examines finer-grained timing cues to stress. A strain-gauge system was used to
examine jaw opening and closing movements in /p(open aye)p/ sequences in
intonationally accented full-voweled syllables, unaccented full-voweled
syllables, and completely stressless (reduced-vowel) syllables produced by four
speakers. Measured values for movement duration, displacement, and velocity
were consistently larger in accented than in unaccented full-voweled syllables.
However, these differences were nowhere near as large as the differences
between full- and reduced-vowel syllables. Reduced syllables also had steeper
velocity-displacement relationships, suggesting a durational difference at the
level of gestural dynamics as well. However, no such consistent difference was
observed between accented and unaccented full-voweled syllables. These results
support the notion that stress contrasts are not uniformly interpreted in the
phonetics at different levels.